Intelligence and Miscellaneous Articles. 411 



influence of the pressure developed, this gas liquefies in the cooled 

 short branch. 



I have in this way obtained several cubic centimetres of pure 

 liquid chlorine. On taking the tube out of the bath, the liquid 

 chlorine commences spontaneous ebullition, and again condenses on 

 the charcoal, while the short branch becomes covered with a frost. 



This succession of phenomena can be reproduced, so to say, inde- 

 finitely ; and the experiments, easy to perform at public lectures, 

 permit the audience to observe the various phases. 



Although I can only consider my experiments a trial, I have ex- 

 tended them to the liquefaction of several gases absorbed by the 

 charcoal when cold and disengaged by a temperature not rising 

 above 100° C. : — chlorine, ammonia, sulphurous, hydro sulphuric, 

 and hydrobromic acids, chloride of ethyle, and cyanogen. The 

 liquefaction of each of these gases can be demonstrated in lectures 

 when explaining the history of those bodies. 



-Reflecting on the feeble thermic effects ascertained by Pouillet 

 when pulverulent mineral matters are soaked with water, oil, alco- 

 hol, or acetic ether, and on the somewhat greater effects exhibited 

 when the same liquids are absorbed by organized substances, I 

 asked myself if we could not succeed in ascertaining pronounced 

 thermic eff: ects by placing in contact with cellules of charcoal liquids 

 which do not act upon it — water, alcohol, ordinary ether, sulphide 

 of carbon, and bromine. 



The experiments exceeded my expectation. For example, with 

 1 part of charcoal and from 7 to 9 parts of liquid bromine, the rise 

 of temperature exceeds 30° C, operating on only from 5 to 10 

 grammes of charcoal'. 



With charcoal well freed from gas, heated and cooled in vacuo, 

 the heating due to the imbibition of bromine would doubtless be 

 much more considerable. 



The volatile liquids condensed in the pores of the charcoal (bro- 

 mine, cyanhydric acid, sulphide of carbon, ordinary ether, and 

 alcohol) are not expelled, or only partially, by a temperature of 

 100° C. at the ordinary pressure. I made the experiment with a 

 Faraday tube, operating as described for the liquefaction of the 

 gases. A tube filled with charcoal saturated with alcohol does not 

 permit any to distil at 100°. 



[The tubes were exhibited to the Academy ; and with them the 

 principal experiments (the liquefaction of ; chlorine, cyanogen, &c.) 

 have been repeated in the laboratory of the Ecole Centrale. 



The condensation of liquid bromine by charcoal, effected upon 

 a few grammes, gave rise to a brisk rise of temperature, the mix- 

 ture passing in a few minutes from 20° to 45°.] — Convptes Rendus de 

 V Academic des Sciences, October 6, 1873. 



NOTE ON THE POSSIBLE EXISTENCE OF A LUNAR ATMOSPHERE. 

 BY E. NELSON, ESQ. 



Owing to the many difficulties with regard to the constitution of 



